Soldering white metal

TC Iron - does it go down to 70 degrees ? Or does it stop at 150+ ? Mine goes properly low, its a Antex 660TC.

Soldering whitemetal to other materials: Tin other material with ordinary solder, a very thin layer. I use normal

60/40 solder. Then tin again with low-melt, over the top of the normal.

Then for whitemetal (to itself, or to other materials): Clean up thoroughly to remove any grease traces. Use an agressive flux (I think I have Carr's red label). Apply small tinning layer onto whitemetal.

Now make joint. This is where low-temp iron really scores because you can raise the temperature without melting the casting. If jointing onto brass/nickel, then heat that material.

Clamp things before making the joints. See article on David Eveleigh's clamps on the 2mm website (below).

Other things which might be worth a try:

- Hot air blower, probably enough to melt the casting if used over enthusiastically, but should melt the low-melt.

- Binding the tinned bits together, then dunk whole lot into boiling water, bring back to boil, then let cool. In theory should melt the low-melt solder.

- Araldite :-) Especially the nice thin runny sorts.

- Nigel

On 10/01/2006 19:11, Just zis Guy, you know? said,

Yes, it is difficult. I must admit that I often use an iron at pretty much full temperature, but very quickly! I find that this means the solder flows quickly without heat travelling into the rest of the casting, so the solder has time to flow before the rest of the casting knows too much about what is happening.

I think a few questions in response to you question might pinpoint the exact problem. Are you trying to solder two whitemetal lumps together, or whitemetal to brass or nickel silver or whatever? In the latter case, 70 degree "solder" will only work with lead-based alloys, so you need to tin the brass piece with normal (leaded) solder first, then solder the whitemetal part to that layer of solder. Did that make sense?

If soldering two biggish whitemetal lumps together, I effectively weld them using the 70deg as filler rod. I do short lengths at a time, and try to keep the whole job cool. For a small part being soldered to a large part, make sure you keep the heat in the larger part, and let it flow through the joint into the smaller part.

I hope some of this helps.

I tend to set my TC iron to about 150 deg C for whitemetal work. Yes, I know it will melt the whitemetal given chance, but as Paul says, get in and out quickly. If I am doing two larger castings, then sometimes the iron will be set higher.

Cheers, Mick

Try this, it has always worked for me.

Keith

Most white metal goes at about 214 C so I find having the iron set at 180 C works for me. I've had my best results with Carr's Red Label and 70 C solder. Clean the joints and put them together apply a brush full of flux. Dip the iron tip in the flux and collect a small amount of solder on the tip, place against the joint and wait. The solder should run in by capillary action when the area is hot enough. For long joints I put a chip of solder on the joint, clean the iron and use it to draw a small pool of solder along the join. HTH

Keith said the following on 10/01/2006 23:35:

There's a lot of bedtime reading there - or for a quiet day at work.....

Pre-heating large parts with a hair dryer, heat pencil or hot air gun works well.

Jeff

It would help if you said what sort of problems are you having? Just can't solder or melting the whole damn thing in the process?

What temp are you setting the iron to?

MBQ

On 11 Jan 2006 00:47:47 -0800, " snipped-for-privacy@hotmail.com" said in :

Solder not flowing properly.

Guy

The prices are a little out of date - most of them are pre-decimalisation! And cyanoacrylate is now much more readily available in several varieties.

OK, thanks all, I think I have got the hang of it now. The major problem is that the solder does not stick to the iron like electrical solder, however...

Of course, this is soldering, isn't it? And what do we know about soldering? Clean the workpiece, clean it again, clean it some more, then give it a quick clean. Then clean (just to be on the safe side), flux, tin, stick. Et viola! Or is it a violin? Anyway, give or take the problem of gaping holes between the parts (easily filled with a judiciously applied iron and some more solder) all now seems to be well. And best of all, if you make a complete pig's ear you just dunk it in a pot of boiling water, pick up the bits and collect the solder when the water's cooled down! Gel superglue? No thanks :-)

Two happy small boys are now admiring their white metal figures :-)

Guy

Make sure you have adequate ventilation!

Since I've started using one of those little extractor fans with built in filter (bought from CPC , IIRC), I find my lungs are a bit less clogged after a kit-building session!

Cheers, Mick